is typically controlled by turning things on and off.
is normally done by JMRI/Jython scripts but many animations
can also be activated from fascia switches on the layout,
so be careful not to stand too close!
that can be turned on and off include lighting, sounds, motors,
relays, and sensors, among others. A Decoder Relay Board (below)
is also used to operate a real telegraph sounder.
Relay Board (DRB) - This is widely used on the layout
to turn things on and off. It consists of a mobile decoder
which drives DPDT relays (with a low-current coil and 5 amp
contacts) from its function outputs,
DRB is based on the use of small DPDT relays with a coil current
in the range of 43 - 65 mA at 12 volts and contacts rated
at about 5 amps (way more than needed for animations and sound).
function output (on a Digitrax DH126 mobile decoder) can provide
up to 100 mA of current and relays on this type of board typically
draw 43 mA. Some small relays can consume more current so
care must be taken not to exceed the limits set by the decoder
manufacturer. Relays of about 60 - 65 mA coil current are
inductive devices (like a relay) are used with a mobile decoder,
it is advisable to put a small diode across the coil because,
when the relay releases, it can create a back current which
could damage the decoder. The proper way to connect such a
diode is shown below.
- Some animation devices use low voltage motors to provide
continuous motion. Examples of these include a rotating stating
rink, an automatically reversing cable car, a children's playground
roundabout, an automobile showroom turntable, and many rides
in the historical park. Some of these devices are controlled
using the motor outputs of a mobile decoder mounted under
the layout. The decoder may be one which is also used for
DRBs or it may be dedicated to a single purpose. Some motorized
devices operate only from switches mounted in the layout fascia.